Here is a list of coarse grains mainly grown in Australia:- 1. Sorghums 2. Millets.
Grain # 1. Sorghums:
The sorghums are a group of cultivated plants which differ widely in growth habit. Variety among the sorghums has been further increased by plant breeders who have given us quite new kinds of sorghum crops.
The grain sorghums are low-growing plants which carry dense heads of grain. The new hybrid varieties have such high productivity that the old open-pollinated varieties are now no longer grown. The grain sorghums are considered to be the most drought resistant of all field crops, and are grown extensively in north-western New South Wales and eastern Queensland.
Sweet sorghums are tall-growing plants with thick stems containing a sugary sap. They are used for silage making and for cutting of winter feed on some coastal dairies.
Broom sorghums are tall plants with fairly thin stems and with a spreading inflorescence which is used to make brooms. These plants are often wrongly named “broom millets”. They are grown in northern coastal districts of New South Wales and in Queensland.
Sudan grass is a coarse grass-like plant which grows to a height of about 1.6 metres. The thin stems bear abundant leaves, and the plant can be used to make hay or can be fed off when well grown.
Sudan grass is one of the quickest growing fodder plants and also one of the most drought resistant. It is grown on the western slopes of New South Wales, in western Victoria and in parts of Queensland.
Sorghum almum is a perennial fodder plant which grows tall stems. It can be grown in drier areas and in summer can yield an abundance of feed.
The most remarkable sorghum fodder plant is however one called Sudex which is a cross between grain sorghum and Sudan grass. Sudex is a very vigorous plant which tillers strongly and produces many tall stems. It is used for making silage, and because of its high yielding ability, it has replaced sweet sorghum and maize as a silage crop in many areas.
All the sorghums are warm weather crops, having originated in tropical Africa. They do best with a mean temperature of 27°C and will not grow below 15.5°C. Sorghums are well adapted to growing in regions of low rainfall, and do quite well if the rainfall is between 500 and 760 mm.
In dry periods they remain dormant, but can recover when rain falls. Even if the main stalks die back, regrowth may occur from buds in the axils of the: lower stem nodes. Sorghums grow well in a wide variety of soils. In a wet season they do best on heavy soils, in a dry season on sandy soils.
One disadvantage of sorghums is that there is always some risk of poisoning when sheep or cattle are grazed on them. At certain stages of growth all sorghums contain substances called glucosides, which, when eaten, are converted into a deadly poison called cyanide.
Horses and pigs do not seem to be affected by this poison. The important facts to know about sorghum poisoning are that the main danger period is when the plants are young, or when regrowth occurs after a dry spell or mowing.
Drought-stricken plants are dangerous, but the risk is less when the crop is turned into hay. Once Sudan grass reaches a height of 45 cm it is generally considered safe for feeding off. Johnston grass is a weedy sorghum which can produce poison, and all crosses between sorghum varieties are very dangerous.
Grain sorghums do best in areas of summer rainfall, but will grow with less rain than is needed by maize. They are often included in rotations with wheat, and a winter fallow is used to conserve moisture in the seed bed.
Late spring cultivation is needed to kill off weeds. The seed is sown in rows 63 to 76 cm apart at the rate of about 9 kg/ha, and should be dusted with Ceresan before sowing.
125 kg/ha of superphosphate is usually applied with the seed. The young crop is cultivated until about 15 cm high, warm days being chosen when the stalks will bend over easily.
Harvesting is usually done with a wheat header, but a wider spacing of the fingers of the comb is desirable. Since the stalks are thick and the crop growth dense, only half the width of the header may be used.
Harvesting must not be done until the grain is hard and dry, otherwise it will sweat and ferment in the bags. Yields of 1681-3363 kg/ha are common, but under ideal conditions on parts of the Darling Downs, yields of much as 8 tonnes per hectare have been obtained. Sorghum grain has about the same food value as maize grain and is good pig feed.
Hybrid varieties of grain sorghum are now grown extensively, and De Kalb E 57 is a popular variety. Another variety, NK 212 shows great promise.
Sweet sorghums are similar in appearance to grain sorghums but are much taller. Well grown Saccaline may reach a height of 3.3 m. Sweet sorghums are very popular on the coast because they are drought- resistant and can be grown on poor soils.
Provided that they are sown at the right time, the stalks remain juicy through the winter, and can be chopped up and fed to dairy cattle. Sweet sorghums are sown in October if grown for silage and in December or later if required as winter feed.
Broom sorghum needs high temperatures and adequate rainfall to do well. It is grown on the coastal districts of northern New South Wales and southern Queensland. The crop is planted in rows 90-100 cm apart at the rate of 2.2-4.5 kg of seed per ha. It is usual to sow at intervals so that harvesting may be spread over a fortnight or so, otherwise there is too much work to do in a short time.
The inflorescence or brush must be bent over or “tabled” at the right time by breaking the stalk 30 cm below the heads, and letting the heads rest over one another across the rows. This should be done when the grain is in the dough stage. After drying out, the heads are taken to the shed and the grain stripped off them by a machine. The heads are then cured by heaping them in layers 10 to 15 cm deep on trays under a roof.
Curing takes 10 to 12 days, after which the heads are graded for size and baled. Heads up to 38 cm long are graded as short, those 38 to 50 cm as medium, and those over 50 cm as long. Yields of broom sorghum vary greatly. 630 kg per ha is a common yield, but when care is taken, yields of 1883 kg of brush per hectare can be obtained.
One of the chief advantages of Sudan grass is its speedy growth. Sudan grass thrives in high temperatures, and can produce quick crops of hay or forage in the Riverina and other parts of the slopes. It is usual to sow it later than maize because a high soil temperature makes more rapid growth.
Since this crop tillers very well, the yield per hectare under good conditions is not increased very much by a thicker sowing of seed. Seventeen kilograms of seed per hectare may be sufficient. The crop is commonly cut for hay when the first heads appear. It will usually grow away again and produce another cut or more green feed. If the crop is to be used for seed, it is usual to save the second growth for this purpose.
Sudex is a crop which responds very strongly to irrigation and to nitrogenous fertilisers such as urea or ammonium sulphate. On irrigated lands in California yields of up to 250 tonnes per ha are said to have been obtained.
Grain # 2. Millets:
These are coarse grasses used for making silage, hay, or to provide grazing. Whereas the sorghums are all closely related plants, the millets belong to different genera, and also differ widely in appearance.
The millets have a very long history of cultivation, and were grown in China in 2000 B.C. They are grown widely in Asia, but have never become very important in Australia, because their shallow root system makes them unable to stand up to dry conditions.
On the other hand, they are quick-growing crops—some maturing in 65 days—and can be used to clean land of weeds. Millets carry no risk of stock poisoning, and are cheap to grow.
The foxtail millets, Setaria spp., have long tapering heads with many bristles appearing between the grains. They are used for making hay. Although the stalks are usually less than 1.8 m in height, they produce a large bulk of hay under good conditions.
These plants are usually the first of all field crops to show the signs of dry weather. Seed at the rate of 17 to 33 kg/ha is sown with a wheat drill. The crop is cut for hay when the first heads appear.
The proso millets, Panicum milaceum, have seed heads which are very branched and usually droop over. They are otherwise similar in growth habit to the foxtail millets, and are grown in the same way.
Japanese millet, or Echinochloa crus-galli, is the most widely grown millet in Australia. Its chief advantages are its freedom from poison danger, and it’s very rapid growth under good conditions. It is more drought resistant than the other millets, but cannot equal Sudan grass in this respect.
It is an annual grass with stems growing 60 to 120 cm in height. The seed head is a compact panicle with 5 to 15 branches, and it looks very like a larger version of its close relative, the weed barnyard grass.
The heads are grey-green in colour. The general cultivation of this crop is the same as for the other millets. Japanese millet can be made into hay, but the stems are thicker than those of Sudan grass, and take longer to dry out properly.
The crop makes excellent silage, and can also be grazed. After grazing it is common to put a cultivator through the crop to loosen the soil and help water to penetrate. Japanese millet will usually make good second growth, and the same crop can be fed off in the early stages and the regrowth later cut for hay.
Pearl millet, or Pennisetum glaucum, is often called by other names such as cat-tail millet or penicillaria. It is a most uncertain forage crop, and is not widely grown.